The present invention relates to a portable unloading device and, in particular, to a portable unloading device for use in combination with a truck having a plurality of bays that has been adapted to receive the portable unloading device. An example of such a truck is a truck used for transporting beer kegs. The truck typically has a number of bays opening to the sides of the truck. Roll-away louvered doors are commonly used. A typical half-keg of beer weighs 160 pounds. The kegs are often loaded on pallets of 6 kegs, for example, stacked 3 pallets high in each bay. Other types of beverage trucks are loaded in a similar manner. Barrel beer is normally removed by hand from such a truck because of the weight of each keg and height the keg is stored, the unloading activity can be dangerous. The top pallet of barrels is especially dangerous because of the height which is typically 84 inches above ground level and the top of the barrel is 104 inches above ground level. Unloading beer barrels has often produced back and other injuries.
Various loading and unloading devices have been disclosed in the past, such as, U.S. Pat. No. 800,166 dated Sep. 26, 1905 issued to Ralph A. Morgan, discloses a motor truck utilizing a jib-crane pivoted at the side of the truck-platform and arranged to swing over the truck-platform to place loads thereon or remove them therefrom. In U.S. Pat. No. 1,378,014, dated May 17, 1921, issued to Lewis Eger is disclosed a loading device including a frame having guides with a carriage movable on the guides. The carriage is adapted to carry a barrel or other object. A lever is provided for raising the carriage and arranged to move over and partially around the carriage and the object carried thereby. In U.S. Pat. No. 2,512,988, dated Jun. 27, 1950, issued to Eli J. Adams, is a device for loading and unloading milk cans and the like to and from vehicles. The device comprises a pair of upright hollow tubular posts secured on opposite sides of a truck. Crane boom arms are provided which rotatably engage posts near the upper ends. A lifting cable is provided which extends down through the bore of a tube and through the floor and floor socket of the truck, then extends over a pulley which is rotatable about a shaft affixed to the other side of the truck body. The cable is then extended around another pulley which is rotatable on a pin extending vertically through the longitudinally movable piston shaft.
In U.S. Pat. No. 3,578,179, dated May 11, 1971, issued to Richard T. Fujioka, is disclosed a portable jib crane adapted for use with modular sealable ship containers. The ship crane of the Fujioka invention includes a support portion that has been adapted for cooperating with a corner casting of a conventional container. It also includes means at the lower part thereof adapted to engage opposite sides of the usual corner post portion of the container. In U.S. Pat. No. 3,845,869, dated Nov. 5, 1974, issued to Blane E. Sellers, is disclosed a portable loading and unloading device which includes a boom. Means are provided which are pivotally connected to the boom for securing the boom to the side wall of a cargo compartment. The means includes a first portion that is to be received in a complementary shaped recess adjacent to a row of vertically spaced perforations in the side wall of the truck and a second portion including a plurality of first elements for latching to the side wall remote from an access opening thereto and holding a first portion in the recess. The first and second hook elements each include a portion adapted to be laterally slidably received in predetermined perforations.